UFactory XARM User Manual page 59

Note: It is highly recommended to use a protection diode for inductive
loads as shown below.
2.5.3.2. Configurable Input
The digital input is implemented in the form of a weak pull-up resistor.
This means that the reading of the floating input is always high.
Users must follow the electrical specifications set in the 2.4.1 'universal
specification'. This example shows how a simple button is connected to
a digital input.
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